Commonly used sedatives called benzodiazepines are associated with an increased risk of pneumonia when used in people with Alzheimer disease, according to a study.

Dementia, of which 60-70 percent of cases are Alzheimer disease, is a risk factor for pneumonia, and many people with dementia are prescribed benzodiazepines and non-benzodiazepines (called Z-drugs), both of which have sedative effects. "An increased risk of pneumonia is an important finding to consider in the treatment of patients with Alzheimer disease," said Heidi Taipale from the University of Eastern Finland.

"Benzodiazepines and Z-drugs are frequently prescribed for this population, and long-term use is typical. Pneumonia often leads to admission to hospital, and patients with dementia are at increased risk of death related to pneumonia," Taipale added. The study, published in CMAJ (Canadian Medical Association Journal), showed that benzodiazepines were linked to a 30 percent increased the risk of pneumonia in patients with Alzheimer disease, and the risk was highest at the start of treatment (during the first 30 days).

The sedative nature of benzodiazepines may increase the risk of pneumonia by increasing the aspiration of saliva or food into the lungs, the researchers said. "Benefits and risks of the use of benzodiazepines should be carefully considered for patients with Alzheimer disease and include the risk of pneumonia," Taipale noted.

For the study, the team analysed at data of 5,232 patients taking benzodiazepines and 3,269 patients taking Z-drugs with Alzheimer disease between 2005 and 2011 in Finland.